Abc control device



July 4, 1933. N. A. wAHLBERG 1,916,400

ARC CONTROL DEVICE Filed Aug. 22, 1928 2 Sheets-Sheet l INVENTOR ATTIORNEY July 4, 1933. N. A. WAHLBERG ARC CONTROL DEVICE Filed Aug. 22, 1928 2 Sheets-Sheet 2 /7 fTgZ INVENTOR M75 /7 Nah/b rg ATfORNEY Patented July 4, 1933 UNITED STATES PATENT OFFICE ELECTRIC 8a MANUFACTURING COMPANY,

A QOBPORATION OF PENNSYLVANIA ARC CONTROL DEVICE Application filed August 22, 1928. Serial No. 301,289.

My invention relates to arc-control devices and articularly to means for controlling the emulsion of flashover arcs associated with high-voltage insulators.

One object of my invention is to provide a device ofthe. above-indicated character that shall ensure the occurrence of fiashover free of the insulator surface, revent cascading between the units of a. series unit insulator, increase the flashover value-of an insulator, confine the occurrence of arcoven to a definite position or positions, properly control arcs under windy conditions and protect an insulator against both gradual and steep-front voltage surges.

Another object of my invention is to provide an arc-control device for the above-mentioned pur oses, that shall be constructed of elements aving sim le symmetrical or standard forms where y to facilitate and economize manufacture, assemblyand renewal of parts and to render the operation of the device efi'ective in service.

In copending application, Serial No. 277,016, electrostatic field-eontrol device filed May 11, 1928, by Julius J. Torok and assigned to the Westinghouse Electric and ManufacturingCompany, is set fortha de" vice upon which this invention is an improvement and toavhich reference may be had for a more complete understanding ofthe features herein set forth.

Ingeneral, as set forth in the above-idem tified copending application, the invention includes electrostatlc-field-directin and distributing elements, associatedwit the terminals of an insulator, that are. so constructed and related to each other and to an insulator having spaced metal parts distributed therealong as to have substantially the SUI'8-V0li2flg6 characteristics of-sphere gaps re tive to each other and the sur e v0 tage characteristics of needle aps re a.- tive to the above-mentioned distributed metal parts of the insulator.

The electrostatic stress, between the insula tor terimnals, is so widel distributed and directed through a zone a ong, but removed from the insulator and so reduced in intensity between said zone and the insulator as to ensure the occurrence of fiashover free of the insulator in response to a surge of y 1 Further, the above-mentioned zone may be limited to a predetermined position, or a plurality of such zones may be provided, each limited. to a predetermined position about the insulator, so that an arc of any kind may be caused to occur in any desired position.

In accomplishing the above-described results, a structure of new and peculiar form is required which might, if not carefully considered from alla'n'gles of construction and operation, result in a structure of relatively expensive manufacture, difliculty of installation, andmainteuance in effective operating posithinv and condition and extreme difiiculty, if not..'impossibility, of renewal of damaged parts.

Accor tnre' that shall retain substantially all of the efiectiye and advantageous o crating features oi the: device 0' the co endingapplica-tion and, at thesame time,

terially economize its-manufacture, facilitate its assembly and, installatiom, permit the ready'renewal of damaged parts, without the loss oithafls fim S ructure, andto otherwise so modify-the device as to render the present inventions. distinct advance there- OVBF'H l Figure '1, of the accompanying drawings, is a side elevational view of a. structure embodying my invention;

Fig. 2 is a top plan view of the upper portiou-of the structure shown in Fig. '1, the insulator and other parts being removed;

' Fig.3 is an elevational view of'a portion of the device adjacent to the lower end of Fig. 1, taken at right angles thereto;

Fig. 4 is a detail cross-sectional view of a portion. of the device, taken along the line IVIV of Fig. 2; v

Fig. 5 is a view, similar to Fig. 4:, indicating a modified form of structure;

Fig. 6 is a fra entary sectional View of a slightly modifie portion of the device cor- 4 so constructed of parts of simple or standard form as to ma- V dmg1y,it is my aim to provide a strueresponding to the lower left-hand portion thereof, as viewed in Fig. 2;

Fig. 7 is a view, similar to Fig. 6, of a still further modified form of the structure there of;

Figs. 8 and- 9 are yiews, on a reduced scale, of a modified form of' thc invention, as illustrated, re=pecti\'ely, at the lower portion of Pi 1 and iii-Fig.3, and. v

"igs. -10' a nd 11 are views, similar to Figs. 8 and 9, of a further modified form of the invention- The device comprises, in general, an insulator 2, a member 3 at the upper end thereof for mounting the same on a, tower or other usual ground support, a clamp-4 mounted at the lower end of the insulator 2 for supporting a transmission-line conductor 5 and upper and lower electrostatic-field or arecontrol devices 7 and 8, respectiyely, of my invention. 5 i

' The insulatorfi is'iif a; isnaljserie's-unit suspension type but may be of other types, my invention eing particularly adapted for iasulatois embodying dielectric and metallic parts distributed through orhloiig'the same, such as insulating "parts wand metal caps 12 and pins 14, respectively'," ')f the insulator 2.-

.The clamp 4 may be of any siiitubleltype but, as shown, i'slof zitype, jwhicli perniits' the conductor '5 to slip 'threthrtiugh under certain conditionsimd taeminboa of the clamp and'the cdndfictof about an axis through substantially the of the conductor.

"Each of the a i-c coi'itro' l-"elerni'nts'fl niid 8 is preferably in theform of a loop'of modified oval or elliptical shape; having major and minor axes; viewed in one direction; as

1' 5x Fig; 2; and of siib'stantiallv'U-ship, viewed in'andthei- '(lirectionjii's'in i :.I," oom p 07 side portions '11 bemoan? *small miter-s surface area and end p i-5031s {8 b'f ranxiveiy great outer-surface new."

-The" side 1 portions'l'l of each-(if the: ele

' ments 7 and 8 are preferably disposed entire lyat cneand; at .the-Jsameside of theplane 05 the :lower :and upper surfaces thereof, re'-.

, spectively aboxg-mntioned, the, portions-11 oitheupper eleineutlbeingmboye the lower surfaces, and-the" portions ,17 ,of the lower, ele-. ment digging belowthe uppersurfacasof the a d m m eislii't iereof. :Ihe side Portions 17, are also providedwith portions 19 which merge or extend gradually bet ree1 i the end members 13 and the intermediate portions 20 of the 'side portions 17,1for a purpose, to be hereinafter set forth;

Suitable members 21 are connected torthe side members 17,: asby welding or other suit able means, for mounting the upper element 7 to the cap 12 of the upper insulating unit and the lower element 8 to the clamp l.

The end members 18 are each preferably constructed of standard tubing, as indicated in Figs 1 2, 3, at, 6 and7, having substantielly unil orm cross-sectional area throughout or, as indicated in Fig. 5, a similar member 22 may be constructed of sheet metal having at least the main are-controlling surface ortions thereof of uniform cross-sectiona area. throughout, a consideration being symmetry of cross-section to facilitate and economize manufacture.

The side members 17, while illustrated as of rectangularcross-section, may be of any othersuitalile shape and',--preferably,' of the same shape throughout to "facilitate and economize manufacture from standard rod or tubing material, a consideration being that they should be of materially reduced surface a'rea, 'as compared with the areas of the m'cmbe'rs or portions 18.

In the"abov e-des'cribed structure, mainly of Figs.- 1, 2 and'3, the upper and lower end portions 18 resent'relativel extensive co'nuctiu'gsu ace areas toeac other to relatiircly \iiidelydistribute" the field'ibetween the'se 'snrflices and to provide a'brealtdoivn characteristic therebetwee'n like the'hreek downehmcierisuc betweeiitwo' spheres of relatively f 'co'nducting "areas; Such characteristics, irrespective of whether the frbntdfiiifsiir e wane be sitee'p or gradual,- cau'sesthe' relatavel .un'iforin widelyalistril u'te'd field between" e upper and lower coact ing I8'tb. be disrupted before flashover will occur in a needle-gap field or a field whiclrisinoreconfceiitrated at the terminals. On an oth''riha'nd, the field betnfeen-any of the meagr -18am im'yofit'he caps'12 is nonfm'or' concentrated at the cap, thereby this indie! the characteristic 5 F9 1 .rings'li'er'etoforc empibyed; thr'hfas' hot sufii'cient distincie between. t i ype s' 'P be n t af aminethems an be -We wthe. lattera'nd the metal; arts of suspension inin: response to 51' steep-front Y surge jiave,lflas li over occurred betweexi'tl e capspf adjacent: iii imiaclion known as cascading rihichds prevented.- by the device ofrmyjnvention,

' Whenfan; arc occursibetireeii eiltherof the oppositely disposed pairs of members 18 during windy conditions,:.and ii the archangs onfdr-a-sufiicient length of'time} it may be blown toward the one or the other end of the members 18, to the portions 19 and thence to the intermediate portions 20 of the side inembers 17, during 'which transition, the arc is gradually transferred from "the large-area member 18 to the small-area" member. 17 and lio so attenuated or drawn out in length as to be extinguished.

With the side members 17 secured to end members 18 by readily operable securing means, such as screws or bolts 23, when one of the parts is damaged by arcs, it maybe easily renewed without scrapping the entire structure.

Also, the ends of the side members 17, in stead of being secured to the outer surfaces of the end members 18, as illustrated in Fig. 1, may be secured to the inner surfaces of the members 18, as indicated in Fig. 6.

Fig. 7 shows the end members 18 extended slightly beyond the side members 17 and provided with rounded cap members 24 which serve as closure means for, and as means for preventing concentration of the field adja cent to, the ends of the members 18. Other means could, of course, be provided for closing these ends, such as plugs of any suitable character or flat plates fitted over the openings in the ends.

In Figs. 8 and 9, the structure is substantially the same as that shown in the previous figures with the exception that members 25, corresponding to the end members 18, are an gularly disposed relative to the positions thereof shown in Fig. 1. In this form, the centers of the members 25 adjacent to the major axis of the device, as shown in Fig. 2, are in the same plane, and the gradual transition of the arcs, under wind conditions, effected partially by the slope of the end members 25 and partially by the slope of the ends 19 of the side members 17.

In each of the above-described forms, the end members 18 and 25 are of simple-curve form. In Figs. and 11, the structure is also similar to those above described but members 26, corresponding to the end members 18, instead of being of simple curvature, or curved about a single center point, are of compound curvature, or curved about more than one center. Thus, as viewed in plan, as in Fig. 1, the members 26 have curves in a horizontal plane similar to the members 18 and, as viewed in end elevation, as in Fig. 11, they have curves in a vertical plane.

The latter structure localizes the ultimate arcing zone to an even greater extent than in the structures of the previous figures, permits side members 27, corresponding to the side members 17, to be straight throughout the lengths thereof and effects the above-described transition of the arcs under wind conditions while they are still extended between one of the upper and one of the lower members 26.

While I have shown and described particular forms of my invention, changes may be effected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as my invention 2-- 1. An arc-control device comprising an element of substantially loop-shape embodying spaced perimetral portions of substantially the same cross-sectional area throughout, said portions having electrostatic-fieldcontrol surfaces in substantially the same plane at right angles to the axis of the loop, and perimetral portions of smaller cross-sectional areas between said first perimetral portions in offset relation to the plane of said surfaces whereby said first perimetral portions are caused to initially receive the arc.

2. An arc-control device comprising an element of substantially loop-shape embodying sheet-metal perimetral portions of the same cross-sectional area throughout, said portions having surfaces in substantially the same plane at right angles to the axis of the loop and perimetral members of smaller cross-sectional area than said sheet-metal portions disposed between the same in offsetrelation to said surfaces whereby said sheet-metal members are caused to initially receive the arc.

3. An arc-control device comprising substantially a loop element constructed of endto-end-related perimetral sections of different cross sectional areas each of substantially uniform cross-sectional area throughout to cause different degrees of electrostatic-stress distribution adjacent thereto.

4. An arc-control device comprising a loop including diametrallv-opposite perimetral sections of substantia ly the same cross-sectional area throughout, said sections having electrostatic field-conrol surfaces in substantially the same plane at right angles to the axis of the loop, and perimetral sections of smaller cross-sectional areas between, and joined to, said diametrically-opposite sections in offset relation to said plane whereby said diametrally-opposite sections initially receive the are.

5. An arc-control device comprising a loop including tubular perimetral sections of the same diameter throughout, said sections having surfaces in substantially the same plane at right angles to the axis of the loop, and perimetral sections of smaller cross-sectional areas between, and joined to, said tubular sections in ofiset relation to said plane whereby said tubular sections initially receive the are.

In testimony whereof, I have hereunto subscribed my name this 15th day of August NILS A. WAHLBERG. 

